title: Chronic inflammation role in the obesity-diabetes association: a case-cohort study.
abstract: BACKGROUND
  Chronic inflammation is related to both obesity and diabetes. Our aim was to investigate to what extent this inflammation contributes to the association between obesity and diabetes.
  
  
  METHODS
  Using a case-cohort design, we followed 567 middle-aged individuals who developed diabetes and 554 who did not over 9 years within the ARIC Study. Weighted Cox proportional hazards analyses permitted statistical inference to the entire cohort.
  
  
  RESULTS
  Obese individuals (BMI≥30 kg/m2), compared to those with BMI<25 kg/m2, presented a large increased risk of developing diabetes (HR[obesity]=6.4, 95%CI 4.5-9.2), as did those in the highest (compared to the lowest) quartile of waist circumference (HR[waist]=8.3, 95%CI 5.6-12.3), in analyses adjusted for age, gender, ethnicity, study center, and parental history of diabetes. Notably, further adjustment for adiponectin and inflammation markers halved the magnitude of these associations (HR[obesity]=3.2, 95%CI 2.1-4.7; and HR[waist]=4.2, 95%CI 2.8-6.5). In similar modeling, attenuation obtained by adding fasting insulin, instead of these markers, was only slightly more pronounced HR[obesity]=2.7, 95%CI 1.7-4.1; and HR[waist]=3.6, 95%CI 2.3-5.8).
  
  
  CONCLUSIONS
  The marked decrease in the obesity-diabetes association after taking into account inflammation markers and adipokines indicates their major role in the pathways leading to adult onset of diabetes in obese individuals.
authors.affiliation: Graduate Studies Program in Epidemiology, School of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil. vivi_luft@yahoo.com.br.
authors.forename: Vivian C
authors.initials: VC
authors.lastname: Luft
authors.forename: Maria I
authors.initials: MI
authors.lastname: Schmidt
authors.forename: James S
authors.initials: JS
authors.lastname: Pankow
authors.forename: David
authors.initials: D
authors.lastname: Couper
authors.forename: Christie M
authors.initials: CM
authors.lastname: Ballantyne
authors.forename: J Hunter
authors.initials: JH
authors.lastname: Young
authors.forename: Bruce B
authors.initials: BB
authors.lastname: Duncan